After following a seven-game, Round 1 win over the Leafs with four straight losses to Tampa Bay at the end of Round 2, the Bruins understand they didn’t raise their game as required. Brad Marchand, who expressed regret for bringing unwanted attention to the team, believes progress can continue next season.

Mike Loftus The Patriot Ledger

BOSTON -- The youngest, least experienced Bruins feel they’ve learned a valuable, if difficult lesson.

They’re not alone.

Three mornings after what they thought could be a long Stanley Cup challenge ended with a fourth straight Round 2 loss to the Lightning, the Bruins gathered on Wednesday morning for exit interviews at Warrior Arena. They expressed disappointment, optimism, and in at least one case, regret.

“I think the biggest thing for me now,” said winger Brad Marchand, who led the B’s with 85 regular-season points before adding 17 more in 12 playoff games, “is to really take a pretty hard look in the mirror, and realize the actions, some of the things I’m doing, have much bigger consequences than I may ever think or really believe will come out of it.

“The last thing I ever want to do is bring the embarrassment on my teammates and the organization that I did.”

Marchand, of course, was referring to a Game 4 incident in which he licked Lightning forward Ryan Callahan during a confrontation -- the second such incident of the playoffs. Unlike the tongue-to-neck contact with Leo Komarov in Round 1, the Callahan incident resulted in league-wide criticism, and a warning from the NHL about potential discipline if Marchand repeated such behavior.

Suspended by the NHL six times previously (once each in the last four seasons) and fined on three other occasions, Marchand says he’s tired of attracting attention for actions besides performance.

“I have to be a lot better,” he said. “I know I’ve said that in the past, but that’s got to be the thing I really work on most. I think I’ve kind of gotten my game to a pretty decent spot, and I’ve got some character things … that clearly need some fixing.”

While alone on Wednesday in feeling compelled to express contrition, Marchand was among a group who felt some good should come from the Bruins’ rapid exit from Round 2 after winning Game 1 in Tampa, 6-2.

“I think the biggest thing we can take away from it all -- even the older guys -- is just how much more intense, how much you really have to raise your game, to be at that next level,” Marchand said. “It’s one thing to get through that first round, but every round after that gets even harder.”

Second-year winger Noel Acciari, who made his postseason debut a year ago, had his eyes opened a second time.

“I learned that each round gets harder,” said Acciari, who will soon undergo a procedure to repair a sports injury sustained in November. “First round, we go to Game 7 against a good (Maple Leafs) team and prevail, and then it gets even harder in the second round. We just have to make sure we’re ready for that.”

Defenseman Torey Krug, who missed the playoff finale with an ankle fracture that won’t require surgery, but will keep him off his feet for two months, didn’t think the B’s handled postseason success well enough.

“We wanted to make sure we didn’t have that emotional letdown after Game 7” against the Leafs, Krug said. “We were making sure everyone was aware it was only going to get harder from there.

“I thought we did a decent job in Game 1 … but from there on out, it really picked up. (The Lightning) pushed back pretty hard. I think it was an eye-opening experience for a lot of guys.”

First-time playoff participants like Scituate native Ryan Donato, who followed 12 regular-season games after ending his Harvard University career in March with three postseason appearances, feel they gained valuable, albeit ultimately disappointing experience.

“Playoffs are another jump,” Donato said. “It continued to get faster and faster.

Once you have that experience, you kind of know where you need to be. Now I know what I need for next year.”

Around the boards: Patrice Bergeron (groin) and captain Zdeno Chara (upper body) said they were hoping rest and rehabilitation would allow them to avoid offseason surgery. Rookie winger Jake DeBrusk (shoulder) said he’d need a month before determining if surgery is his best option. … David Backes, sent out of Game 5 after a helmet-to-helmet collision with the Lightning’s J.T. Miller, said “I haven’t seen the chart, but that (a concussion) would be my guess.” … David Krejci and David Pastrnak left Wednesday for Denmark, where they’ll join the Czech Republic team in the IIHF World Championships.